Phonet: routing table Netlink interface

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 161 insertions, 0 deletions

diff --git a/net/phonet/pn_dev.c b/net/phonet/pn_dev.c
index 71fffa587783..6d64fda1afc9 100644
--- a/net/phonet/pn_dev.c
+++ b/net/phonet/pn_dev.c
@@ -240,6 +240,27 @@ static int phonet_device_autoconf(struct net_device *dev)
         return 0;
 }
 
+static void phonet_route_autodel(struct net_device *dev)
+{
+        struct phonet_net *pnn = net_generic(dev_net(dev), phonet_net_id);
+        unsigned i;
+        DECLARE_BITMAP(deleted, 64);
+
+        /* Remove left-over Phonet routes */
+        bitmap_zero(deleted, 64);
+        spin_lock_bh(&pnn->routes.lock);
+        for (i = 0; i < 64; i++)
+                if (dev == pnn->routes.table[i]) {
+                        set_bit(i, deleted);
+                        pnn->routes.table[i] = NULL;
+                        dev_put(dev);
+                }
+        spin_unlock_bh(&pnn->routes.lock);
+        for (i = find_first_bit(deleted, 64); i < 64;
+                        i = find_next_bit(deleted, 64, i + 1))
+                rtm_phonet_notify(RTM_DELROUTE, dev, i);
+}
+
 /* notify Phonet of device events */
 static int phonet_device_notify(struct notifier_block *me, unsigned long what,
                                 void *arg)
@@ -253,6 +274,7 @@ static int phonet_device_notify(struct notifier_block *me, unsigned long what,
                 break;
         case NETDEV_UNREGISTER:
                 phonet_device_destroy(dev);
+                phonet_route_autodel(dev);
                 break;
         }
         return 0;
@@ -287,10 +309,19 @@ static void phonet_exit_net(struct net *net)
 {
         struct phonet_net *pnn = net_generic(net, phonet_net_id);
         struct net_device *dev;
+        unsigned i;
 
         rtnl_lock();
         for_each_netdev(net, dev)
                 phonet_device_destroy(dev);
+
+        for (i = 0; i < 64; i++) {
+                dev = pnn->routes.table[i];
+                if (dev) {
+                        rtm_phonet_notify(RTM_DELROUTE, dev, i);
+                        dev_put(dev);
+                }
+        }
         rtnl_unlock();
 
         proc_net_remove(net, "phonet");
diff --git a/net/phonet/pn_netlink.c b/net/phonet/pn_netlink.c
index d21fd3576610..d8f5d3fb9ee2 100644
--- a/net/phonet/pn_netlink.c
+++ b/net/phonet/pn_netlink.c
@@ -29,6 +29,8 @@
 #include <net/sock.h>
 #include <net/phonet/pn_dev.h>
 
+/* Device address handling */
+
 static int fill_addr(struct sk_buff *skb, struct net_device *dev, u8 addr,
                      u32 pid, u32 seq, int event);
 
@@ -160,6 +162,131 @@ out:
         return skb->len;
 }
 
+/* Routes handling */
+
+static int fill_route(struct sk_buff *skb, struct net_device *dev, u8 dst,
+                        u32 pid, u32 seq, int event)
+{
+        struct rtmsg *rtm;
+        struct nlmsghdr *nlh;
+
+        nlh = nlmsg_put(skb, pid, seq, event, sizeof(*rtm), 0);
+        if (nlh == NULL)
+                return -EMSGSIZE;
+
+        rtm = nlmsg_data(nlh);
+        rtm->rtm_family = AF_PHONET;
+        rtm->rtm_dst_len = 6;
+        rtm->rtm_src_len = 0;
+        rtm->rtm_tos = 0;
+        rtm->rtm_table = RT_TABLE_MAIN;
+        rtm->rtm_protocol = RTPROT_STATIC;
+        rtm->rtm_scope = RT_SCOPE_UNIVERSE;
+        rtm->rtm_type = RTN_UNICAST;
+        rtm->rtm_flags = 0;
+        NLA_PUT_U8(skb, RTA_DST, dst);
+        NLA_PUT_U32(skb, RTA_OIF, dev->ifindex);
+        return nlmsg_end(skb, nlh);
+
+nla_put_failure:
+        nlmsg_cancel(skb, nlh);
+        return -EMSGSIZE;
+}
+
+void rtm_phonet_notify(int event, struct net_device *dev, u8 dst)
+{
+        struct sk_buff *skb;
+        int err = -ENOBUFS;
+
+        skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
+                        nla_total_size(1) + nla_total_size(4), GFP_KERNEL);
+        if (skb == NULL)
+                goto errout;
+        err = fill_route(skb, dev, dst, 0, 0, event);
+        if (err < 0) {
+                WARN_ON(err == -EMSGSIZE);
+                kfree_skb(skb);
+                goto errout;
+        }
+        rtnl_notify(skb, dev_net(dev), 0,
+                          RTNLGRP_PHONET_ROUTE, NULL, GFP_KERNEL);
+        return;
+errout:
+        if (err < 0)
+                rtnl_set_sk_err(dev_net(dev), RTNLGRP_PHONET_ROUTE, err);
+}
+
+static const struct nla_policy rtm_phonet_policy[RTA_MAX+1] = {
+        [RTA_DST] = { .type = NLA_U8 },
+        [RTA_OIF] = { .type = NLA_U32 },
+};
+
+static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh, void *attr)
+{
+        struct net *net = sock_net(skb->sk);
+        struct nlattr *tb[RTA_MAX+1];
+        struct net_device *dev;
+        struct rtmsg *rtm;
+        int err;
+        u8 dst;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        ASSERT_RTNL();
+
+        err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_phonet_policy);
+        if (err < 0)
+                return err;
+
+        rtm = nlmsg_data(nlh);
+        if (rtm->rtm_table != RT_TABLE_MAIN || rtm->rtm_type != RTN_UNICAST)
+                return -EINVAL;
+        if (tb[RTA_DST] == NULL || tb[RTA_OIF] == NULL)
+                return -EINVAL;
+        dst = nla_get_u8(tb[RTA_DST]);
+        if (dst & 3) /* Phonet addresses only have 6 high-order bits */
+                return -EINVAL;
+
+        dev = __dev_get_by_index(net, nla_get_u32(tb[RTA_OIF]));
+        if (dev == NULL)
+                return -ENODEV;
+
+        if (nlh->nlmsg_type == RTM_NEWROUTE)
+                err = phonet_route_add(dev, dst);
+        else
+                err = phonet_route_del(dev, dst);
+        if (!err)
+                rtm_phonet_notify(nlh->nlmsg_type, dev, dst);
+        return err;
+}
+
+static int route_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+        struct net *net = sock_net(skb->sk);
+        u8 addr, addr_idx = 0, addr_start_idx = cb->args[0];
+
+        for (addr = 0; addr < 64; addr++) {
+                struct net_device *dev;
+
+                dev = phonet_route_get(net, addr << 2);
+                if (!dev)
+                        continue;
+
+                if (addr_idx++ < addr_start_idx)
+                        continue;
+                if (fill_route(skb, dev, addr << 2, NETLINK_CB(cb->skb).pid,
+                                cb->nlh->nlmsg_seq, RTM_NEWROUTE))
+                        goto out;
+        }
+
+out:
+        cb->args[0] = addr_idx;
+        cb->args[1] = 0;
+
+        return skb->len;
+}
+
 int __init phonet_netlink_register(void)
 {
         int err = __rtnl_register(PF_PHONET, RTM_NEWADDR, addr_doit, NULL);
@@ -169,5 +296,8 @@ int __init phonet_netlink_register(void)
         /* Further __rtnl_register() cannot fail */
         __rtnl_register(PF_PHONET, RTM_DELADDR, addr_doit, NULL);
         __rtnl_register(PF_PHONET, RTM_GETADDR, NULL, getaddr_dumpit);
+        __rtnl_register(PF_PHONET, RTM_NEWROUTE, route_doit, NULL);
+        __rtnl_register(PF_PHONET, RTM_DELROUTE, route_doit, NULL);
+        __rtnl_register(PF_PHONET, RTM_GETROUTE, NULL, route_dumpit);
         return 0;
 }